Fluoride is a mineral that’s crucial to bone health, but many people receive doses that are either too high or too low to be beneficial. According to the World Health Organisation (WHO), the acceptable daily limit for fluoride is 1.5mg per litre. It’s common practice to add fluoride into drinking water, dental products, and food to ensure that children and adults receive an adequate amount of this important mineral.

However, not all countries experience a lack of fluoride in their environment. In India, an increased level of fluoride has been observed in ground water and soil used to grow food. This has resulted in an unsafe level of fluoride for the general population, especially in domestic drinking water. Read on to learn more about the dangers of fluoride in unsafe levels and how activated carbon can be used in water filtration.

The Benefits and Dangers of Fluoride

The medical community accepts that fluoride is an important mineral that must be consumed in the proper doses. When people maintain a fluoride level between 0.5 and 1.5mg/L they experience a safe level of exposure. This amount of fluoride contributes to bone health, including protection against dental issues like cavities.

However, an overabundance of fluoride leads to toxicity. Toxic fluoride levels can cause dental and skeletal fluorosis. Fluorosis leads to pitting in teeth that damages their structural integrity, while ligaments throughout the body become calcified, causing pain and permanent disability. Furthermore, toxic levels of fluoride will enter soft tissues, causing irreversible blood, brain, and liver damage.

The Importance of Defluoridation and Options for Filtration

Due to the obvious dangers of fluorosis, it is crucial to filter and treat water to either reduce or eliminate the presence of fluoride. This process can be conducted in many ways, but it is always referred to defluoridation. There are three general processes of defluoridation.

Electrocoagulation relies on electrolysis to bring fluoride and other particles to the surface. These particles collect and bind in a frothy structure, which allows for easy removal. However, treating vast quantities of water with electrolysis is an expensive option. Ion exchange is another process where unstable ions, such as aluminium is introduced to the water. These ions bind with the fluoride and create a stable compound.

The third option, which we will focus on in this article, is adsorption. Adsorption allows substances like fluoride to bind to a filtrating material, such as activated carbon. Activated carbon is comprised of millions of microscopic pores that can trap particulate matter. It’s a highly economical form of water treatment, even with special additives to increase performance.

Choosing a Raw Material for Adsorption

Some example materials used in adsorption are include burnt clay, coconut shell carbon, and activated carbon. The drawbacks to options like clay and coconut shells include higher costs, general ineffectiveness, or the creation of unusable or undesirable by-products, such as sludge. We use activated carbon, which can easily be sourced from a coconuts. These materials are heated and ‘activated’ to increase their adsorption property.

As previously mentioned, activated carbon has many small pores to trap and neutralize fluoride in water. Just 1 gram of activated carbon has 500m of filtering surface area, making it highly cost-effective. However, the filtration capabilities can be further improved by adding chemical treatments to the activated carbon. This ensures that the highest amount of fluoride is removed and neutralised to produce safe drinking water.

Evaluating the Effectiveness of Chemically Treated Activated Carbon Filters

Our team conducted an experiment to test the effectiveness of our activated carbon filters. These water samples contained toxic levels of fluoride.

Performance of Fluoride Block

Liters	Gallons	Influent	Effluent	Reduction Level
8ppm ± 0.8ppm	<4ppm	%
10	2.6	8.08	1.80	77.72
25	6.6	7.92	2.40	69.70
50	13.2	8.00	2.50	68.75
100	26.4	8.00	3.00	62.50
125	33.0	8.00	3.60	55.00
150	39.6	8.00	3.80	52.50
175	46.2	8.00	4.00	50.00
200	52.8	8.00	4.80	40.00

The results showed that activated carbon filters treated with our in-house formula were able to quickly reduce the amount of fluoride in the water samples.

It is clear that fluoride levels from any water source can be lowered by utilizing activated carbon filters treated with our in-house formula. With maximum purification occurring in only three hours, this method of adsorption can easily be adopted for domestic, public, or manufacturing use.